The present invention relates to mounting stands for portable audio devices and, more particularly, to stands configured to enhance sound output from such devices.
Portable music players and other audio devices with built-in speakers are becoming increasingly popular. Such devices may be designed purely as music or audio players or may be portable electronic devices with a variety of other functions, which are further configured to operate as music players. For example, cellular telephones, personal digital assistants (PDAs) and the like are now available that may be used to play music and other sounds for a user. The music may be stereophonic, with different respective audio tracks directed to different speakers of the portable audio device.
Such portable audio devices may have, for example, speakers facing toward the side and back of the device. Thus, when the speakers are used with the device placed on its back or side, one of the speakers may be blocked. In other orientations, for example, the back speaker faces forward, but the side speaker faces up. As such, there may be no optimal arrangement for directing both speakers toward the listener, particularly in electronic devices designed to provide capabilities other than playing music. Such a design may arise, for example, as the speakers generally have a minimum physical size and they may generate strong magnetic fields. As such, placement options for the speakers in a compact device may be limited. As a result of problems with RF interference and the like, placement in a cellular phone with the ability to be used as a music player may be even more problematic. In addition, as they are portable devices, a device designer is also limited as the orientation and location of the portable device relative to a listener in use is highly unpredictable.
One approach to providing improved audio is the use of external accessories, such as portable amplified speakers, FM modulators, line-level audio adapters, and so forth. Such accessories may take advantage of the increasing audio quality and drive of portable music devices and, with these increased capabilities, more users may see such devices as a portable means of carrying their entire music collection with them to parties, and so forth. However, playing a device through loudspeakers, as opposed to earphones, or use of other active powered accessories, places a greater drain on the battery of the portable audio device and/or may require auxiliary amplifiers or the like with their own power sources.
Amplified speakers for portable devices may amplify the sound, but are powered instead of passive. Other sound-reinforcing technology is known. For example, the Bose Wave system delays sound in a resonant tube so as to achieve positive reinforcement on exit. Passive radiators are used in some speaker systems, where the main driver excites a non-driven (passive) speaker cone. The passive speaker is generally a distinct device (basically a speaker without a driver) mounted in the same box as the active driver. Another passive device is a driver that can be attached to a wall or table to directly excite the surface and cause the surface to function as the radiator. In this case, the driver generally must be physically coupled to the passive resonator and it acts as a dedicated speaker.